The invention comprises a method for producing a plastic vehicle attachment part, a plastic vehicle attachment part, and its use.
As part of increasingly stringent requirements regarding carbon dioxide emissions of motor vehicles, there are also strong efforts to reduce the weight of a vehicle and thus its fuel consumption. Constant innovations in the plastics sector enable the replacement of large parts of the metal car body by correspondingly lighter elements made of polymeric materials. In particular, parts of or even the entire window region can be replaced by elements made of polymeric materials. In many cases, along with a significantly lower weight, these present hardness, stability, and toughness comparable to that with a car body window made of steel. In addition, due to the weight reduction, the center of gravity of the vehicle is moved lower, which has a positive effect on handling. Moreover, compared to metals, polymeric materials can be produced, processed, and shaped at significantly lower temperatures. This reduces the energy demand and costs during production of the materials.
Molded parts made of polymeric materials can be produced in virtually any desired shape and geometry. Special high-performance plastics such as aramide or kevlar, for example, have very high strength and stability.
Many material parts made of plastics must satisfy various requirements and functions. In this regard, important parameters are stability, fracture behavior, scratch resistance, impact strength, or notched impact strength. In addition to technical considerations such as weight and strength of the individual components, shape, geometry, and appearance also play an increasingly important role. Especially in the automobile industry, along with mechanical properties, characteristics in the area of design and aesthetics are also of great significance.
In order to combine various characteristics in polymeric materials, they are composed of basic materials of different shapes and different natures. Established methods for producing these materials include two-component or multicomponent injection molding methods. It is thus possible to combine characteristics such as weather resistance, surface gloss, and fracture resistance or torsional stability with each other. In addition, the relative content of very expensive materials can be reduced.
DE 197 22 551 A1 discloses a method for producing plastic parts in the two-component injection molding process, wherein one of the layers is made of a solidly colored plastic.
EP 1 743 756 A1 discloses a method for producing a component using an injection molding process, in which, in a first step, a thermoplastic plastic is injected between two foils. In a second step, the first molded part thus produced is bonded to a second molded part by back injecting the first molded part with a second thermoplastic plastic. The production of such a component is relatively expensive.
EP 1 190 831 A1 discloses a method for producing a vehicle window pane made of a plastic in an injection molding process. An A, B, C, or D pillar trim is sprayed onto the vehicle window pane as a second component. The pillar trim can be decoratively colored.
The publication “Automobilscheiben aus Kunststoff [Automobile Glazings Made of Plastic]” by C. Hopmann et al. (Kunststoffe [Plastics], Carl Hanser Verlag, Munich, No. 2/05, Feb. 1, 2005, pp. 22-27, XP002396333, ISSN: 0023-5563) discloses methods for producing plastic automobile glazings and the use of varnishes for coating plastic glazings. The article further discloses that, for protective purposes, a film can be applied to a polycarbonate pane.
EP 0 415 716 A1 discloses a plastic auto glazing that is provided with a protective coating and has a frame part. This window pane is produced in an injection molding process.
DE 10 2008 023 499 A1 discloses a printing varnish and a method for producing an imprinted laminate.
One established method for producing optical effects is the method for film insert molding (FIM). In this method, an appropriate film is laid in the injection mold and back injected with a suitable plastic. In this manner, the surface properties and geometry of polymeric materials can be affected and modified selectively and versatility. Temperature-stable films are an important prerequisite for the use of the method of film insert molding. Moreover, imprints situated on the film must also be temperature resistant enough to survive back injection with a liquid polymer such as polycarbonate. Since the film is positioned on the outside of the workpiece, it is not protected against external mechanical and chemical influences. In the long run, this can result in damage to the film and the imprint contained on the film.